Automobile headlight control system



June 9, 1959 v. H. WILEY ETAL AUTOMOBILE HEADLIGHT coNTRoL SYSTEM Filed Jan. 1a, 1955 3 Sheets-.Sheet 1- 1m( NToRs June 9, 1959 2,890,387

v. H. WILEY ETAL h AUTOMOBILE HEADLIOHT CONTROL. SYSTEM Filed Jan. 1a, 1955 3 Sheets-Sheet 2 llllllllllllllll r r l f Q2/2 I 50@ )214 @9 709/ 6" 7 26g-1 a: M @FM J f June 9, 1959 v. H. WILEY ETAL 2,890,387

AUTOMOBILE HEADLIGHT CONTROL SYSTEM Filed Jan. 18. 1955 3 Sheets-Sheet 3 United States Patent f 2,890 ,387 'AUTOMOBILE IilEADLIGHT'C-NTROE SYSTEM 3 Claims. (CESI/SL83) The .present invention relates -Vto motor vehicle yhead.

light' control systems,l more particularly to .controlsystems for automatically dimming, the .headlights of f auto-,t

mobiles or the like andthe invention has for an object the provision of a headlight` control system, and'switching apparatus for ,use therein which causes the headlight beams' to. be. automatic'ally loweredupon the approach ofan oncoming vehicle.

Numerous control systems and apparatus for use therein.

are known in the priorart for. .electronically and electromechanically jselecting., one ofthe beams Vofmulti-beam headlights-of automotive vehicles. to automatically de-` press.'` the maximumlrange beams of` suchl headlights or togothrwise reduce the lightY intensity therefromfwhen two'or more automotivewehicles approachone another. inV such almanner that'the bright lights therefrom might. temporarily jblin'd'the respective.. automotive vehicle operators to thereby` .create adangerous drivingthazard. Alf` though` such automaticv systems generally function satisf, factorily to automatically dim the headlamps to vobviate such driving hazards,` like all automatic. systems, they are subject 'to failure. In the event that the automatic headlight control system should fail,..itV is-.desirable. if not .altogether necessary, that the driver of`,the.vehicle have manual control ofthe multi-range headlights.v Other. wise, the operation of the vehicle on the highway would be..a constant source of danger. Furthermore, .circumstances frequently exist where it is desirable for the driver to be able to quickly over-ride the vautomatic system, even when it isoperating` satisfactorily.

Anotherobje'ct of theipresent 4invention is, therefore, to provide a new and improved automatic control system for use with headlight .beams .of `an automotivevehicle, and whichperrnits the operator lof the vehicle to control the headlights manually if desired, this manual, control being available instantly inthe case,of.emergency,.ir respective of lthe condition of, the automatic system..

Another object of the present inventionis to V.provide alnew andY improved automatic headlight dimmerhaving means manually operable atV all times` to overrule the automatic mechanism.

A further object ofthepresent invention isA to provide a new and improved automotive vehicle headlight dimmer utilizing-a single actuating member for overrulling'th'e automatic system and for depressing-or. raising the beams of multirange headlights.

A `still further objectof thepresent `invention is to provide afnew and improved automotive headlight control .system which enableswthe driver ofthe vehic1e..to overrule. the automatic. system and to manually switch the .headlight beams. by meansof a single actuation.y of arpluuger operated switch- A` still further object of theapresentA invention is to provide a new and improved automatioheadlight. control system wherein the response timeof the headlight beam condition to change inv lighting conditions is extremely rapid.L

Briefly, -fin'accordanceV with the present invention there 2,890,387 Patented June 9, 1959 ICC is, provided a system, for automatically dimming the` headlightsof van automotive vehicle in response to light` energy Y from-an. approaching -vehicle impingingv upon a light sensitive device and vforquickly restoring the headlights to the highbeam condition when the approaching vehicle has passed. A manually operableswitch is provided fo`r overriding'the `automatic system-to reverse the position of the headlightV beams and is` so connected in, circuit with. the automatic system such that the system is alternately switched-between automatic and manual operation in response to vsuccessive actuations of the manually operable switch' actuatingmember.

The invention, both as to its organization and method of; operation, ,together withffurther objects and advantages thereof, will best'be understood by referenceto the following detailed'descriptiontaken in connection with` the accompanyingl drawings in which:

Fig.l is' agschematic, somewhat diagrammatic, circuitl diagramof a preferred embodiment of oneA phase of the presentinvention showingpan automatic headlight control` system;

Fig. 2 is a.. partial sectional front elevation view ofa preferred embodimentof another phase of the present invention showing improved switching apparatus which finds particular application in-the headlight controlsystem of`.Fi'g. l;

FigtBis a sectionalside elevation View takenalongl Fig'.' 4 'is afront elevation sectional View takenalong the line 4-4 in Fig. 3, assuming the entire switching mechanism. is .shown'ethereing Fig., 5"'is afragmentary sectional view of the switchingapparatusof Fig. 2 v'showing the manually operable switch, actuatingjmember in the depressed position;

Fig. 6"is a fragmentarysectionalview .of .the switch-4 ing ',apparatus of Fig.V 2 -taken along line 44-4 of Figl 3` showing the'manually operable actuating member. in-the depressed; position;

Fig. 7 is'a fragmentary sectional view similar tn Fig. 2 inwhichthe switching mechanism shown is in a different plosition of operation;

Fig.l 8 is a fragmentarysectional view similar to that of Fig.- 6v` showing the switch'in themanual loperating condition;

Fig, 9`is`a-top elevation sectional view taken along the line-9i+9iin Fig.I 2;'.

Fig.A l0"`is` a perspective view of a slidable support member; and

Figs; lla. andllb are diagrammatic illustrations of the; over-center springr and toggle arrangement.. Before considering the detailed aspects of the present invention as illustrated in-the several iignres of the drawingsyitshould be pointed outthat .automatic headlight control-systems are relatively -new whereas manually controlled 'systemsfor selectively switching the means of multi=beam headlights have been widely knownandfused for many years. Because of this familiarity` gained through many years of use, the average motorist instinctiv'ely' actuates the conventional foot operated plunger type'of yheadlight control switch when therer arises an emergency condition ,which dictatesthat his' headlight beam should/be either depressed or raised.

In view ofths, the presentinvention incorporates the conventionalV foot-operated plunger in a headlight switching apparatus control whereby/the driver of the automomotivevehicle'is able to `instinctively take control of the position'ofhisheadlight beams without any consideratio'nwhatso'ever to the condition of the automatic control-mechanism; If, for example, the motor vehicle operator sees that his headlightbeams are switched in one positionjan'dhe desires that theybe in the other position, he merely depressesv the conventionalH foot-operated plunger to quickly and positively switch the headlight beams to the desired position. Furthermore, the manually controlled switching apparatus is equally effective to change the position of the beams whether or not the automatic control system is operating satisfactorily. Upon the termination of the emergency condition which induced the driver to switch the system to the manually operable position, another similar actuation of the footoperated plunger automatically returns the system to automatic operation and at the same time switches the headlights to the other beam position.

Another point which must be considered in the design, and manufacture of automatic headlight beam control systems, is the rapidity with which the beams are returned to the high beam condition after the approaching vehicle has passed. It has been suggested to incorporate time delay apparatus in headlight control systems to prevent return of the system to the high beam condition when the vehicle incorporating `the automatic equipment passes over bumps in the road or makes a sharp turn to avoid an obstruction such, for example, as a hole in the road. Furthermore, the systems as taught by the prior art are inherently slow acting unless special, usually expensive, provisions are made to decrease the response time.

While holes and bumps in present day highways are quite uncommon, it is not unusual for an automotive vehicle to pass a single approaching vehicle on a dark, winding, country road. In the latter case it is very important that the headlights be returned to the high beam condition as soon as possible to prevent overdriving of the headlights and the consequent dangerous driving hazard.

A preferred embodiment of the present invention for effecting the aforesaid results, generally includes a vibrator for converting the direct voltage of the conventional automobile battery into an alternating voltage for the energization of an electronic control circuit which includes a light sensitive element for producing a voltage having a magnitude responsive to the intensity of light impinging thereon, and a discharge device connected in a novel circuit arrangement for amplifying this voltage to control the operation of a switching relay. The switching relay selectively controls a solenoid operated headlight beam control switch to connect either the high or low beam filaments of the automobile headlights to the automobile battery for energization thereby.

In order to enable the driver to take control of the headlights when an emergency condition arises, the solenoid operated beam control switch is provided with the conventional foot-operated plunger, the actuation of which, overrules the controlling solenoids therein to place the switch in the other operating position and to change the system to the manually operating condition.

Referring now to the drawings and particulary to Fig. l, wherein a headlight control system includes a conductor adapted to be connected to one terminal of a conventional automotive vehicle battery to provide a source of power energization for a conventional vibrator circuit 12 which provides alternating operating voltages on the conductors 14 and 16. Specifically, the vibrator 12 includes a vibrating element 18 having a magnetically movable center contact member 20 connected to ground. Stationary contact members 22 and 24 are respectively connected to the ends of an inductor 25 which forms the primary winding of a transformer 26. The inductor 25 is connected to be supplied lat the center tap 28 thereof with direct voltage energy from the battery through the conductors 10 and 30. A bypass capacitor 32 is connected between tap 28 and ground to bypass any radio frequency waves generated in the vibrator which might interfere with the operation of a radio receiver in the motor vehicle. A pair of secondary Windings 34a and 34b are provided on the transformer 26 and adapted to be energized by the magnetic field estab- 4 lished by current in either half of the inductor 25. One end of each of the secondary windings 34a and 34b are connected to ground through a pair of conductors, 36a and 36b, respectively, and the other ends are respectively connected through the conductors 14 and 16 to an amplifier and relay circuit 37 and to a conventional light sensitive device 38. A buffer capacitor 42 is connected across the secondary Winding 34b and is used to tune out transients .generated in the vibrator thereby to provide a substantially square waveform of voltage on the conductor 14.

The light sensitive device 38, which is preferably mounted at the foot of the motor vehicle so as to be energized by that light which would ordinarily interfere with the safe operation of the motor vehicle by ternporarily blinding the driver thereof, may conveniently include a conventional photo-multiplier discharge device 44 having a cathode 44a connected through a resistor 46 to the conductor 16 for energization by the alternating voltage provided thereon from the vibrator assembly 12. A plurality of multiplier electrodes 44b are connected through a conventional resistor network 48 and a resistor 50 to ground so as to provide at an anode 44C of the discharge device 44 a voltage indicative of the amount of light impinging on the cathode 44a. The anode 44C is connected to supply current to a pair of variable grid resistors 52 and 54 of an electron discharge. device amplifier 56 to effect energization of a switching relay 58 in response to the light impinging on the device 38. In order to smooth out the peaks in the A.C. signal supplied to the control electrode of the amplier 56, a capacitor 53 is connected in parallel with the `grid resistors 52 and 54. The resistive network 48 is provided in connection with the photomultiplier 44 in place of the conventional multi-tap transformer to permit the use of a more compact light sensitive device without the necessity of connecting a multiplicity of conductors thereto.

The relay 58 includes an energizing coil 60 which is connected between the conductor 14 and the anode of the device 56, a pair of shunting members 62 and 64, and contacts 62a, 62h, 64a and 64b. When the coil 60 is energized the shunt 64 is positioned so as to connect the contact 64a to ground, and the shunt 62 is positioned so as to connect the contact 62a with a conductor 63. When the coil 60 is deenergized (the position shown) shunt 64 is disconnected from the circuit and shunt 62 interconnects contact 6211 with the conductor 63.

The system as thus far described is operable to selectively connect the contact 62a or the contact 62b to conductor 63 in response to the lighting condition affecting the light sensitive device 38. In order to control the headlight beams of the automotive vehicle in accordance with the lighting condition as evidenced =by the position of the shunt 62 of the switching relay 58, a combination solenoid or manually operated switching apparatus 66 is connected to one `side of Ithe vehicle battery through the conductor 10 and to the other side 0f the battery through the section 62 of the switching relay 58, the latter side including the vehicle ground system.

The switch 66 is provided with a shunt 68 adapted to selectively connect the conductor 10 to the central contact 70 which is connected to the high beam filaments or to the central contact 72 which is connected to one side of the low beam filaments, the other side of the filaments being grounded. Thus, when the shunt 68 interconnects the conductor 10 and the contact 70, the high beams are energized, whereas when the shunt 68 interconnects the conductor 10 and the contact 72, the low beams are energized.

In order to automatically control the position of the shunt 68, a pair of control solenoids 74 and 76 are connected to be selectively energized in accordance with the condition of the switching relay 58. In the diagrammatic unoccupied .control contact, 770 ,or '72. facilitate ,actuation 0`f-theplungcr`84, aswitch 86 which ,is connected in the ground return .path of the control .solenoids74 and 76between conductor `63 and ground is .adaptedto be alternatelynpenedand closed in response `.shunt 68 .at .the point `7,-8aintermediate the ends thereof. (A pair ofmagnetic .c ores `80.and 82 are attached to oppositeendsof .the .rod .78 and adapted to |be moved llaterallyinresponse to energization otone or the other of vthe solenoids 74, 7.6. Accordingly, when the solenoid .74 isenergized, the lcore '80 is drawn'therein, laterally .moving therod .78 .to the vlet to energize high beam ,.lilaments. ,gized,.the core 82 is drawn therein, laterallyV moving the ,rod 78 to thel right to energize the low beam filaments.

Conversely, when the solenoid 76 is ener- Manual .ovenruling ofthe automatiecontrol system is `.provided ,by means of a plunger operated actuating member 84 which is adapted to move .the shunt 68 to the In order to tosuccessive .actuations .of the .plunger 84 and is so .actuated thereby .as to open the .ground path of 'the `solenoids.prior. to theactual physical moving of the shunt 68.by.the mechanical actuating member. 'Whereas one l.phase of 4thepresentinilention teaches a particular construction for the control .switch 66, other constructions .may,=.0 f course, be utilizedin ,the ysystem illustrated in Eig. l. Forexample,.a ratchet type switch 86 may be .employed to open and close the solenoid ground return lpath in, response to successive actuations of the plunger 84.

The operation ofthe control system as illustrated in Fig. 1 will now be described. The switch 86 being closed, the system is .in the automatic condition with .the solenoid 76 energizedso as to vconnect lthe low Ibeam filaments in circuit .with the battery. Consequently, it

.may-be, assumed that another vehicle is approaching such .that a suliicient amount of light is impinging upon the cathode 44a of the photoelectric multiplier tube 44 to :elfecta highcurrent between the cathode 44a and the .anode .44c-whichestablishes a-negative bias across the .resistors 5,2 and 54 to l.cut olf the discharge device '56.

When the device '5.6 .is cut olf, the relay coil @6.0 of the relay 58 is ,deenergized to move the shunts Y62 and 64 in ycontact .with their b contacts. In this .position the solenoid l76 is energized through the shunt .62 so as .to actuate .the switch .66 to connect the ,conductor 10 4with.thelowbeamheadlight filaments. When, however, theapproaching vehiclehaspassed such that the incident .light onthephotoelectric multipliercathode 44a is dimin- .isl:1ed,` the voltage developed across the resistors 52, 54 is .reduced so that the discharge device 56 is rendered .conductiveand the coil 60 ofthe relay S58 is energized. When the relay ."5-8 is energized, the junction between the resistors 52 and S4 is connected to .ground through the contact 64a .andtheshunt 64, and the solenoid 74 is energized through vthe contact 62a Vand .the shunt 62 thereby toenergize -the -high Abeam filaments. `It may be seen, therefore, that when the control switch is in the @high beam position theload resistanceconnected )to the .anode 44o of the .photomultiplier .tube 44 is reduced so .as -to decrease the sensitivity thereof by a factor of .-approximately two to one. Accordingly, when the relay 58 Vis deenergized so as to change from -high -beams to low beams, .the sensitivity of .the photomultiplier tube 44 is increasedimmediately after the dimmingoperation to prevent the reenergization of the-high ibeams when I,thearheadlights of lthe .oncoming vehicle are Iswitched .from .the high beam to the low beam position and the .light strikingthe lcathode 44a is correspondingly reduced. When .the system is in automatic operation and the shunt .member y68 of the switch 66 is in contact with .either lthe highv beam contact .70 .or the low beam contact 72, actuation of the switch 84 opens the ground circuit to both of the'solenoid windingsvand throws the shunt member 68 to the other vcontact position. The release of thevplunger of the switch -84 doesnot close theswitch 86 and the solenoids remain deenergized. When it'then becomes desirable for an operator to utilize the other headlight beams, another actuation and release of the plunger of the switch 84 will once more'close the switch 86--thereby completing the circuit 'between the shunt ,62 and ground, whereby the automatic system includingthe relay 58 and the discharge device 56 takes over control of the headlight beams.

The rapid response of the autonraticsystem is economically obtained by the use `of the two secondary windings 34a and 34b on Athe transformer 26 whereby the anode and Vcontrol electrode of the discharge device 56 are A.C. energized hy in phase signals. The value of the capacitor 53 is relatively small and is selected to provide satisfactory .iiltering of the control signal from the photomultiplier 38 without introducing any appreciable time delay into the overall Vcontrol system.

Referring to Figs. v2 through 10,.there is shown therein a headlight control switch including a housing cornprising an integral body portion,102 an'd a cover member 108 adapted to be received ,within a rabbit .106, best shown in Figs. 3 and 9, which is provided about the open end of the body portion 102. To provide a relatively dust-freespace for housing the principalparts of the switching mechanism, an annular gasket 109is positioned `on therabbit 106 between the cover 108 and 'the housing -body portion 102.

A pair of control solenoids $110 and 11'1, which correspond'to the solenoids 74 and 76 in Fig. l, are provided 'for electromagnetically positioning the contact members of the switch '10() in response to a switching signal supmatic control circuit of Fig. l. In order to support `the solenoids 110 and 111 within the housing and to permit facile access thereto for both initial .assembly and repair, a plurality of integral members 5112, 114, 116 and 118 depend from the cover 108 into the housing cavity. A cross-member 119, best shown in Fig. 9, interconnects the inner ends of the depending members 112, 114, 11'6, 118 for added mechanical strengthand to support certain parts of the switch mechanism to be more fully described hereinafter. The solenoids 110, 1411 are supported in `the .outer cavities defined by the depending members 112, 114, 116, :118 and the crossmernber'119 ,by means of slots.120, 122, 124, 126 which are adapted to receive the ends of a pair of sleeves 128 and 130 upon which the coils of solenoids 110, .1`11 are respectively wound. In order to symmetrically mount the solenoids 110, '111 with respect to the depending members, the sleeve supporting slots 120, 122, 12'4, 12'6 are centrally located intermediate the ends of thedepending members and extend approximately one-half the distance therethrough parallel with the plane of the housing cover 18S. Theinner ends of the sleeve supporting slots are arcuate, thereby to loosely conform to the outer surface of the sleeves 128, 130. In order to prevent lateral movement of .the solenoid sleeves 128 and 130, the slots 120 and 126 in the outer depending members 112, 118 are slotted recesses not fully extending through the thickness of the depending members and the slots 122, 124 areprovided with inwardly extending shoulders 122a and 124e.

In order to selectively connect the automotive vehicle battery which is connected to terminal 153 in circuit with the high or low beam headlight laments which are respectively connected .to terminal lugs 157 .and 159 a solenoid controlled slidaljle contact .support member (best shown in Fig. l0) is mounted in a guide channel 141 (Fig. 3) provided in a depending ,member 142 which extends perpendicularly from the housing cover 108 Ibetween the members 114, 116 and orthogonally thereto. The guidechannel 141 extends laterally along the longitudinal axis of the solenoids 110, 111 thereby to permit guided movement of the Contact support member 140 in response to forces applied thereto along the longitudinal axis of the solenoids 110, 111. To provide such forces in response to control current in one or the other of the solenoids 110, 111 magnetic cores 143 and 144 are mounted along the principal axis of the slidable support 140 on integral extending portions 145 and 146, respectively. The cores 143, 144 are generally cylindrical in shape and positioned so as to -be received within the solenoid sleeves 128, 130 and are spaced apart by such an amount such that at any one time only one core can be symmetrically located with respect to a control solenoid. It will thus be seen that energizing of solenoid 110 draws the core 143 within the sleeve 128 thereby moving the slidable support 140 to the left. Conversely, energization of the solenoid 111 moves the support 140 to the right.

A contact member 147, which is formed from a flat sheet of a conductive material, such, for example, as copper, is provided with a pair of rectangularly shaped tabs 147a and 147b extending from two diagonally opposite corners of the rectangularly shaped body portion thereof and which are bent back over the edges of the support 140 to secure contact member 147 to the support 140 and to provide a pair of conductive paths between the top and bottom thereof. A lbottom contact member 149, which is secured to the inner Wall of .the housing `cover 108, protrudes into the housing intermediate the members 114, 116 beneath the member 142 and has an upwardly self-biased leaf spring portion 150 extending through a control slot 154 in member 142, thereby to provide a sliding contact with the bottom surface of the contact 147. The contact member is conveniently secured to the housing cover 108 by means of a conductive rivet which additionally secures the terminal lug 153 to the outer surface of the cover 108 and provides atconductive path between the lug 153 and the contact 149. The contacts 149 and 147 correspond in operation to the pivoted shunt 68 in the embodiment of Fig. l and may be connected to the automotive vehicle battery through the terminal lug 153.

A low beam lament leaf spring contact member 156 and a corresponding terminal lug 157 (Fig. 9) are rivetted to the cover 108 in the Contact 149. The Contact 156 depends within the switch housing above the slidable support 140 and is self-biased against the support 140 at the forward intermediate portion thereof. The contact portion 15611 of the contact 156 is offturned, thereby to contact only a relatively small portion of the lsupport 140 such that when the support is i-n the full left position (solenoid 110 being actuated), contact 156 is pressed against the tab 147b whereas when the support 140 is in the full right position (solenoid 111 being actuated), the conductive path between contact 156 and tab 146b is broken. A high beam filament :leaf spring contact member 158 and corresponding terminal lug 159 are similarly riveted yto the housing cover 108. The contact 158 depends within the housing above the slidable support 140 and is provided with an voturned contact portion 158a which is self-biased against the rearward intermediate portion of the support 140. The Contact por- `tion 158a is similar to the contact portion 156e and only bears against the contact tab 147a when the slidable support 140 is in the ull right position (solenoid 111 being energized). The switching apparatus 100 as thus far described may be used to switch current from the automotive vehicle battery to one set of headlight filaments in response to the energization of solenoid 110 and `to another set of headlight filaments in response to the energization of solenoid 111.

In order to enable manual control of the position of the slidable cont-act support member 140 with respect to the contact members 156 and 158 irrespective of the condition of the automatic system, an integral upstanding ear 166 is centrally located on the slidable support and is provided with an elongated aperture 168. A force transmitting bifurcated toggle member 170 is provided with elongated slots in the downwardly extending tines thereof and is attached to the ear 166 by means of swing pivot member 172 which is mounted for pivotal movement about its ends in apertures provided in the cover member 108 and in the cross member 119. The upstanding portion of the toggle 170 is covered by means of a resilient member 174 which is adapted to be biased against one or the other of channel defining members 176 and 177 which extend downwardly and forwardly `from the upper and rear walls of the housing by means of an `overcenter` spring 178 which is pivotally mounted at its ends in apertures in the cover 108 and in the cross member 119. The apertures in which the spring 178 is mounted are positioned directly below the apertures in which the swing pivot 172 is mounted.

In order to manually position the slidable support 140 with respect to the high and low beam contacts 156 and 158, a downward force is exerted on the toggle 170 by means of la foot actuated plunger 180 which extends through an aperture in the top of the switch housing and is biased by a coil-ed compression spring 181 in an upward position against the stop formed by the toggle actuating member 188 abutting against the bottom surface of the top wall of the switch housing. A conventional cover button 184 is secured as by rivetting to the top of the plunger 180 and member 188 is secured to the plunger 180 by the 'action of a spring plate 189 which is riveted to member 188 and adapted to be received along one of its edges in an annular recess 180a provided near the lower end of the plunger 180. A cylindrically shaped plunger housing 182 is secured to the top of the switch housing and adapted to telescope within the button 184 during manual lactuation of the switch 100. The Iforward end of the toggle actuating member 188 is otftumed at 188a toward the bottom of the switch 100 and relieves the stress on the ear 166 by preventing forward stress on the toggle when the plunger is actuated so as to depress the toggle 17 0.

When the slidable support 140 is in the full left position as illustrated in Fig. 2, a downward force on the button 184 and consequently the toggle actuating member 188 is resolved into a downward vertical force and la rightwardly directed lateral force on the swing pivot and consequently on the ear 166 which forces the slidable support member 140 to the right such that the contact member 158 makes with the tab 147a to connect the terminal lug 157 with the terminal lug 159. As the support 140 is forced to the right, by the depression of the plunger 180, the swing pivot 172 is lowered in the slotted aperture 168 in the ear 166. In order to prevent the ends of the tines of the toggle 170 from bearing against the top of support 140 during this condition of operation, a pair of slots 189 and 190 are machined on opposite sides of the ear 166.

Reference is directed to the diagrammatic illustration of Figs. 11a and 11b for a better understanding of the operation of the toggle 170 and the otcenter spring 178 for forcing the support 140 to the unoccupied position in response to a downward force exerted on the toggle 170. In Fig. 11a, the toggle 170 4is shown in solid lines occupying its normal position when the support 140 is in the full left postion and in dotted lines for the support 140 in the full right position. Fig. 1lb shows the toggle 170 in an intermediate position during movement of the support 140 from one postion to the other.

Referring to Fig. lla it will be observed that when the support 140 is in the full left position, the spring 178 exerts a force on the toggle 170 in a direction whereby to pivot it in a counterclockwise direction about the pivot point 170a thereof. When the support 140 is in the full right position, the spring 178 exerts a force on the toggle 170 in a direction whereby to pivot it in a clock- ,direction about ,fthe pivotpoint "170e thereof; {Re- "ferring to xFig. 4'11b it maybe observed that when the toggle 170 is in an upright position andthev pivot point 170a is alignedlwith jthe-springand swing pivot support apertures, anupwardly directed verticaltorce is exerted .bythe spring 178 on the toggle 170 and no movement is .effected thereby. "When, vhowever, the pivot v.point 170a .ftween ,",thejlsupport apertures, vthe Yspring 178 ,exerts a eounterclockwise "for'ce'whichis partially resolved into a lateral force on the toggle 170 which forces the slidable support 140 to the full left position. The overcenter spring and swing pivot arrangement thereby assures the proper positioning yof the support 140 even when the plunger 180 is not fully depressed and also positions the toggle 170 such that the succeeding actuation of the plunger 180 moves the support to the unoccupied position. In addition, the snap action securely positions the support 140 to prevent movement thereof due to sudden jars and continued vibration of `the switch mechanism by the natural vibrations of the automotive vehicle Ias it is driven over rough terrain.

In order to deenergize the solenoids 110 and 111 when the foot operated plunger 180 is actuated there is provided a switch means connected in the ground circuit of the solenoids 110, 111. This switch comprises a contact button '200 which is conveniently attached to the rear wall of the housing 102 by means of an upstanding conductive contact support member 202. In this embodiment, the body portion 102 of the switch housing is constructed of metal and is attached to the metallic body of the automotive vehicle to complete the path between the contact button 200 and ground. Another contact button 204 is arranged to coact with the iirst contact 200 and is mounted on a conductive leaf spring 206 which is supported on an insulating terminal block 208 by means of a screw 209. The block 208 is attached to the rear wall of the housing 102 by means of a threaded screw 210, and a lead 212 (only partially shown), which completes the ground circuit of the solenoids 110, 111, is soldered to the spring 206. A rod-like actuating plunger 214 is constructed of an insulating material and is mounted for slidable movement in a bearing block 216 which is attached to the rear wall of the housing 100. The rearward portion of the toggle actuating member 180 extends downwardly a substantial distance along the :rear wall of the switch housing 102 between the channel members 176, 177. The channel members 176, 177 in addition to acting as stops for purposes of resolving the downward force on the toggle 170, also define a guide path for directing the movement of the actuating member 180. The downwardly extending rearward portion of the toggle actuating member 180 is adapted to lride on a rail 218 which extends vertically along the rearward wall of the housing 102 at the center thereof. A plunger actuating member 220 having an off-turn portion 222 for coaction with the end of the plunger 214 is mounted on ythe member 188 for movement therewith such that during actuation of the plunger 180 the switch actuating plunger 214 is forced against the spring contact arm 206 to break the conductive path between the contacts 200 and 204. The plunger actuating member 220 is so located on the toggle actuating member 188 that conduction between the contact buttons 200, 204 is broken before the slidable support 140 is moved to a new position in response to the downward force on the toggle 170. As a result, there is no force exerted on the slidable support 140 by the control solenoids 110, 111 to counteract or oppose the mechanical force exerted thereon by the member 188.

' gera-ese l yInlrfr'dert alteinately open vand close'thecontrl solei 1.nvid.energizat'ion `circuits upon successive actuations of ,'circuitis complete. When the plunger is partially actuated, however, Ithe plunger 214 is actuatedand thesolenoid ground .circuit is broken '(Fig.. 8), .but the `toggle is not yet actuated. Therefore, the presentfinventionemploys an -oppositely bifurcateddetent 228 which 'iis rotatably supported` near the lower end of the downwardly extending portion of the toggle actuating member y188 which [is adapted to freely pass upwardly-.past a 'for- 'wardly extending shoulder 5229 of the channel member 176 when the inner surfaces of the bifurcated portions of the detent 228 do not engage the shoulder 229 as the plunger 180 is released. When, however, the detent 228 is below the extending portion 229 of channel member 176 and the inner surfaces of the bifurcated portions do engage the shoulder 229 upon the release of the plunger 180, the spring 181 forces the toggle actuating member upward such that the rightwardly extending tine of the detent 228 catches on the shoulder 229 to jam the plunger 180 in a partial downward position (Fig. 8). In this position, the solenoid ground circuit is held open by the force exerted by the plunger 214 on the contact arm 206.

The next succeeding depression of the plunger 180 forces the detent 228 against an upwardly extending caming linger 226 which is offset from the pivot point of the detent thereby to rotate the detent 228 in a clockwise direction by such an amount that upon the release of the plunger 180 the shoulder 229 does not engage the bifurcated ends of the detent 228 and the plunger 180 is forced by the spring 181 to the fully released position. The solenoid ground circuit is thus completed and the system is returned to the automatic condition.

On the next following actuation of the plunger 180, the lower bifurcated end of the detent 228 engages the camming nger 226 (Fig. 6) and is thereby rotated by such an amount that upon the release of the plunger 180, the open bifurcated end of the detent 228 engages the shoulder 229, is jammed thereby, and the system is again in the manually operating condition. The switching mechanism of Figures 2 to ll inclusive, is described and specifically claimed in our divisional application, Serial No. 789,770; filed January 26, 1959.

While there have been described what are at present considered to be the preferred embodiments of the invention, it will be understood that various modifications may be made therein which are within the true spirit and scope of the invention as definted in the appended claims.

What is claimed as new and desired to be `secured by Letters Patent of the United States is:

1. A headlight system for automobiles comprising, a high beam connection; a low beam connection; a battery connection; a low beam controlling solenoid; a high beam controlling solenoid; a single pole double throw switch, selectively acting to connect said low beam connection to s-aid battery connection when lsaid low beam solenoid is energized, said switch selectively acting also, to connect said high beam connection to said battery when said high beam solenoid is energized; a light sensitive device; a sensitive relay under control of said light `sensitive device for selectively controlling current ow through said solenoids, said rel-ay ac-ting to selectively energize said low beam controlling solenoid when light impinges upon said light sensitive device and acting to selectively energize said high beam controlling solenoid when light is absent 4from said light `sensitive device; and, a manually operated foot switch assembly including a plunger, a pair of contacts and a cam mechanism; said contacts being in circuit with said sensitive relay, the :arrangement being such that with each forward movement of said plunger said single pole double throw Switch 11 is moved to its other position, and, with every other actuation of said plunger said cam mechanism serves to hold said contacts of said foot switch assembly open, thereby, in said open position, said .contacts of said assembly disable said sensitive relay tfrorn controlling the energization of said solenoids.

2. Apparatus as claimed in claim 1 characterized by the fact that said sensitive relay includes a coil in the output circuit of an amplier and that the light sensitive device controls a voltage applied to the input circuit of said amplifier.

3. Apparatus as claimed in claim 2 characterized by the fact that said sensitive relay carries an `auxiliary contact, said contact controlling a circuit so as to increase the sensitivity of said amplifier when said contact is 15 2,708,371

12 opened by said sensitive relay and to decrease the sensitivity of said ampler when said last mentioned auxiliary contact is closed.

References Cited in the tile of this patent UNITED STATES PATENTS 1,948,896 Wright Feb. 27, 1934 1,997,209 Douglas Apr. 9, 1935 2,021,041 Altamura Nov, 12, 1935 2,493,307 Moore et al. Ian. 3, 1950 2,558,969 Le Croy July 3, 1951 2,639,339 Franck May 19, 1953 2,684,418 Kock July 20, 1954 2,686,277 Bordewieck et al Aug. 10, 1954 Pashby May 17, 1955 

